var cloneImpl      = require('clone');
var debug          = require('debug')('ff:tcrud:config:util');
var configRegistry = require('./config-registry');

var mod = (function () {
	
	var clone = function(obj) {
		return cloneImpl(obj);
	};
	
	var filterValuePart = function(value,replaceChar,splitChar,partFn) {
		var result = '';
		var parts = value.split(splitChar);
		for (var i = 0; i < parts.length; i++) {
			var part = parts[i];
			if (part.length > 1) {
				result += partFn(part);
			} else {
				result += part;
			}
			if (i < parts.length - 1) {
				result += replaceChar;
			}
		}
		return result;
	};
	
	var copyByTemplate = function(prefix,objectDest,objectSrc,copyTemplate) {
		var keys = Object.keys(copyTemplate);
		var result = [];
		for (var i = 0; i < keys.length; i++) {
			var key = keys[i];
			var value = objectSrc[key];
			if (value === null) {
				//debug('copyByTemplate '+prefix+'.'+key+' src object has null value.');
				objectDest[key] = null;
				continue; // no src value
			}
			var templateValue = copyTemplate[key];
			if (templateValue === null) {
				if (objectDest[key] !== null) {
					//debug('copyByTemplate '+prefix+'.'+key+' has own value: '+objectDest[key]);
					continue;
				} else {
					//debug('copyByTemplate '+prefix+'.'+key+' copy value: '+value);
					objectDest[key] = clone(value);	
				}
			} else {
				
				if (objectDest[key] === undefined) {
					objectDest[key] = clone(templateValue);
				} else {
					//debug('copyByTemplate '+prefix+'.'+key+' going deeper');
					copyByTemplate(prefix+'.'+key,objectDest[key],value,templateValue)
				}
			}
		}
	};
	
	var countTree = function(obj,result) {
		if (typeof obj === 'object') {
			for (var key in obj) {
				result.keys++;
				countTree(obj[key],result)
			}
		} else {
			result.values++;
		}
	};
	
	return function ConfigUtil() {
		
		this.countTree = countTree;
		
		this.copyByTemplate = copyByTemplate;
		
		this.clone = clone;
		
		this.filterValue = function(value,removeChars,replaceChar,partFn) {
			var valueOrg = value;
			for (var i = 0; i < removeChars.length; i++) {
				value = filterValuePart(value,replaceChar,removeChars[i],partFn);
			}
			//debug('filterValue.result: %s from: %s',value,valueOrg);
			return value;
		};
		
		this.stringHash = function (str) {
			var hash = 31; // prime
			for (var i = 0; i < str.length; i++) {
				hash = ((hash<<5)-hash)+str.charCodeAt(i);
				hash = hash & hash; // keep 32b
			}
			return hash;
		};
		
	};
})();

module.exports = new mod();